Dynamic assignment of ACK resource in a wireless communication system

ABSTRACT

Techniques for dynamically assigning acknowledgement (ACK) resource to a user equipment (UE) are described. For dynamic scheduling, a scheduling message may be used to send scheduling information for a single transmission of data. For semi-persistent scheduling, a scheduling message may be used to send a semi-persistent assignment for multiple transmissions of data. In an aspect, at least one field of a scheduling message, which is normally used to carry scheduling information for dynamic scheduling, may be re-used to carry an ACK resource assignment for semi-persistent scheduling. In one design, a UE may receive a scheduling message carrying a semi-persistent assignment and may obtain an assignment of ACK resource from the at least one field of the scheduling message. The UE may receive a transmission of data sent in accordance with the semi-persistent assignment, determine ACK information for the transmission of data, and send the ACK information with the ACK resource.

The present application is a Continuation application of U.S. Ser. No.12/403,327 filed Mar. 12, 2009, entitled “Dynamic Assignment Of ACKResource In A Wireless Communication System,” which claims priority toprovisional U.S. Application Ser. No. 61/040,609, entitled “DynamicScheduling of UL-ACK,” filed Mar. 28, 2008, assigned to the assigneehereof and incorporated herein by reference.

BACKGROUND

I. Field

The present disclosure relates generally to communication, and morespecifically to techniques for assigning resources in a wirelesscommunication system.

II. Background

Wireless communication systems are widely deployed to provide variouscommunication content such as voice, video, packet data, messaging,broadcast, etc. These wireless systems may be multiple-access systemscapable of supporting multiple users by sharing the available systemresources. Examples of such multiple-access systems include CodeDivision Multiple Access (CDMA) systems, Time Division Multiple Access(TDMA) systems, Frequency Division Multiple Access (FDMA) systems,Orthogonal FDMA (OFDMA) systems, and Single-Carrier FDMA (SC-FDMA)systems.

A wireless communication system may include a number of Node Bs that cansupport communication for a number of user equipments (UEs). A Node Bmay communicate with a UE on the downlink and uplink. The downlink (orforward link) refers to the communication link from the Node B to theUE, and the uplink (or reverse link) refers to the communication linkfrom the UE to the Node B. The Node B may send a transmission of data tothe UE. The UE may decode the transmission of data and may sendacknowledgement (ACK) information to the Node B. The ACK information mayindicate whether the transmission of data was decoded correctly or inerror by the UE. The Node B may determine whether to send aretransmission of data or a new transmission of data to the UE based onthe ACK information. It may be desirable to efficiently assign ACKresource to the UE for use to send the ACK information.

SUMMARY

Techniques for dynamically assigning ACK resource to a UE in a wirelesscommunication system are described herein. The system may supportdynamic scheduling and semi-persistent scheduling. For dynamicscheduling, a scheduling message may be used to send schedulinginformation for a single transmission of data. For semi-persistentscheduling, a scheduling message may be used to send a semi-persistentassignment for multiple transmissions of data.

In an aspect, at least one field of a scheduling message, which isnormally used to carry scheduling information for dynamic scheduling,may be re-used to carry an ACK resource assignment for semi-persistentscheduling. The at least one field may include a new data indicatorfield, a redundancy version field, a modulation and coding scheme (MCS)field, a transmit power control (TPC) command field, etc.

In one design, a UE may receive a scheduling message carrying asemi-persistent assignment and may obtain an assignment of ACK resourcefrom the semi-persistent assignment. The UE may obtain an index of theACK resource from at least one field of the scheduling message and maydetermine the ACK resource based on the index. The UE may receive atransmission of data sent in accordance with the semi-persistentassignment, determine ACK information for the transmission of data, andsend the ACK information with the ACK resource.

In another design, a UE may receive a first scheduling message carryingscheduling information for dynamic scheduling and may receive a firsttransmission of data sent in accordance with the scheduling information.The UE may send ACK information for the first transmission of data withfirst ACK resource associated with a resource used to send the firstscheduling message. The UE may receive a second scheduling messagecarrying a semi-persistent assignment for semi-persistent scheduling.The UE may receive a second transmission of data sent in accordance withthe semi-persistent assignment. The UE may send ACK information for thesecond transmission of data with second ACK resource conveyed by thesemi-persistent assignment. ACK resources may thus be conveyed indifferent manners for dynamic scheduling and semi-persistent scheduling.

Various aspects and features of the disclosure are described in furtherdetail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a wireless communication system.

FIG. 2 shows data transmission with dynamic scheduling.

FIG. 2 shows data transmission with semi-persistent scheduling.

FIGS. 4A and 4B show two scheduling messages with different formats.

FIG. 5 shows a processing unit for a scheduling message.

FIGS. 6 and 7 show a process and an apparatus, respectively, forreceiving data with semi-persistent scheduling.

FIGS. 8 and 9 show a process and an apparatus, respectively, forreceiving data with dynamic scheduling and semi-persistent scheduling.

FIGS. 10 and 11 show a process and an apparatus, respectively, forsending data with semi-persistent scheduling.

FIGS. 12 and 13 show a process and an apparatus, respectively, forsending data with dynamic scheduling and semi-persistent scheduling.

FIG. 14 shows a block diagram of a Node B and a UE.

DETAILED DESCRIPTION

The techniques described herein may be used for various wirelesscommunication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and othersystems. The terms “system” and “network” are often usedinterchangeably. A CDMA system may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. cdma2000 coversIS-2000, IS-95 and IS-856 standards. A TDMA system may implement a radiotechnology such as Global System for Mobile Communications (GSM). AnOFDMA system may implement a radio technology such as Evolved UTRA(E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, Flash-OFDM®, etc. UTRA and E-UTRA are part ofUniversal Mobile Telecommunication System (UMTS). 3GPP Long TermEvolution (LTE) is an upcoming release of UMTS that uses E-UTRA, whichemploys OFDMA on the downlink and SC-FDMA on the uplink. UTRA, E-UTRA,UMTS, LTE and GSM are described in documents from an organization named“3rd Generation Partnership Project” (3GPP). cdma2000 and UMB aredescribed in documents from an organization named “3rd GenerationPartnership Project 2” (3GPP2). The techniques described herein may beused for the systems and radio technologies mentioned above as well asother systems and radio technologies. For clarity, certain aspects ofthe techniques are described below for LTE, and LTE terminology is usedin much of the description below.

FIG. 1 shows a wireless communication system 100, which may be an LTEsystem. System 100 may include a number of Node Bs 110 and other networkentities. A Node B may be a station that communicates with the UEs andmay also be referred to as an evolved Node B (eNB), a base station, anaccess point, etc. UEs 120 may be dispersed throughout the system, andeach UE may be stationary or mobile. A UE may also be referred to as amobile station, a terminal, an access terminal, a subscriber unit, astation, etc. A UE may be a cellular phone, a personal digital assistant(PDA), a wireless modem, a wireless communication device, a handhelddevice, a laptop computer, a cordless phone, a wireless local loop (WLL)station, etc.

The system may support data transmission with hybrid automaticretransmission (HARQ). For HARQ on the downlink, a Node B may send atransmission of a transport block and may send one or more additionaltransmissions of the transport block (if needed) until the transportblock is decoded correctly by a recipient UE, or the maximum number oftransmissions has been sent, or some other termination condition isencountered. A transport block may also be referred to as a packet, adata block, etc. The first transmission of a transport block may bereferred to as a new transmission, and each additional transmission ofthe transport block may be referred to as a retransmission.

The system may also support dynamic scheduling and semi-persistentscheduling for data transmission. For dynamic scheduling, schedulinginformation may be sent with each transmission of data and may conveyparameters and resources used for that transmission of data. Forsemi-persistent scheduling, scheduling information may be sent once andmay be applicable for multiple transmissions of data. Dynamic schedulingmay provide flexibility whereas semi-persistent scheduling may reducesignaling overhead.

FIG. 2 shows an exemplary data transmission on the downlink with dynamicscheduling. The transmission timeline for each link may be partitionedinto units of subframes. Each subframe may have a particular duration,e.g., one millisecond (ms). For frequency division duplexing (FDD) asshown in FIG. 2, the downlink (DL) and uplink (UL) may be allocatedseparate frequency channels. Different transmissions may be sentconcurrently via the downlink and uplink on the separate frequencychannels. A Node B may have data to send to a UE and may send schedulinginformation on a physical downlink control channel (PDCCH) in subframet₁. The scheduling information may be sent in one or more controlchannel elements (CCEs) and may include various parameters describedbelow. The Node B may send a transmission of one or more transportblocks on a physical downlink shared channel (PDSCH) in subframe t₁. TheNode B may send the transport block(s) in one or more resource blocksand in accordance with parameters conveyed by the schedulinginformation. The UE may receive the scheduling information from thePDCCH and may process the transmission on the PDSCH in accordance withthe scheduling information to recover the transport block(s) sent by theNode B. The UE may generate ACK information (or UL-ACK), which mayindicate whether each transport block was decoded correctly or in errorby the UE. The UE may send the ACK information on a physical uplinkcontrol channel (PUCCH) in subframe t₁+Q, where Q may be equal to 2, 4or some other value. Q is a subframe offset between the datatransmission on the downlink and the corresponding ACK transmission onthe uplink. The Node B may receive the ACK information from the UE andmay send a retransmission of each transport block decoded in error.

The UE may send the ACK information with ACK resource, which may also bereferred to as PUCCH resource, ACK channel, etc. The ACK resource may beassociated with radio resource, code resource (e.g., an orthogonalsequence, a reference signal sequence, etc.), and/or other resourcesused to send ACK information. For example, in LTE, the ACK resource maybe given by an ACK index n(1)_PUCCH and may be associated with (i) atime-frequency location (e.g., a resource block) on which to send ACKinformation, (ii) a cyclic shift of a Zardoff-Chu sequence used forspreading the ACK information in the frequency domain, and (iii) anorthogonal or Walsh spreading sequence used for spreading the ACKinformation in the time domain.

For dynamic scheduling, the ACK resource to use by the UE may bedetermined as follows:n _(PUCCH) =n _(CCE) +N _(PUCCH),  Eq (1)where

-   -   n_(CCE) is an index of the first CCE used to send scheduling        information,    -   n_(PUCCH) is an index of the ACK resource, and    -   N_(PUCCH) is a parameter configured by higher layers.

N_(PUCCH) may be configured by Radio Resource Control (RRC) andbroadcast to UEs. For dynamic scheduling, the ACK resource may be linkedto the first CCE carrying the scheduling information, e.g., as shown inequation (1). The ACK resource may thus be implicitly conveyed via thescheduling information, and no additional overhead is consumed to sendthe ACK resource assignment to the UE.

For dynamic scheduling, each transmission of data may occur as describedabove. For each transmission of data, the Node B may send schedulinginformation in one or more CCEs and may send a transmission of one ormore transport blocks in one or more resource blocks conveyed by thescheduling information. The UE may send ACK information with the ACKresource determined based on the first CCE carrying the schedulinginformation.

FIG. 3 shows an exemplary data transmission on the downlink withsemi-persistent scheduling. A Node B may send a semi-persistentassignment or grant on the PDCCH in subframe t₁. The semi-persistentassignment may include various parameters for transmissions of data onthe downlink as well as an ACK resource assignment for the uplink. Inone design, upper layers (e.g., RRC) may configure a set of ACKresources, and the ACK resource assignment may comprise an index for anACK resource in the set of configured ACK resources. In another design,the ACK resource assignment may assign any available ACK resource.

The Node B may send a transmission of one or more transport blocks onthe PDSCH in subframe t₁. The Node B may send the transport block(s) inone or more resource blocks and in accordance with parameters conveyedby the semi-persistent assignment. The UE may receive thesemi-persistent assignment from the PDCCH and may process thetransmission on the PDSCH in accordance with the semi-persistentassignment to recover the transport block(s) sent by the Node B. The UEmay generate ACK information for the transport block(s) and may send theACK information in subframe t₁+Q. The ACK information may be sent withthe ACK resource conveyed by the semi-persistent assignment.

For semi-persistent scheduling, the semi-persistent assignment may besent once with the first transmission of data and may be valid for apredetermined time period or until the semi-persistent assignment isrevoked. The ACK resource assignment would be valid for the entiresemi-persistent scheduling interval, which is the duration in which thesemi-persistent assignment is valid. The Node B may send newtransmissions of data in accordance with the semi-persistent assignment,without having to send any scheduling information, during thesemi-persistent scheduling interval. The UE may send ACK information foreach new transmission of data received from the Node B using the ACKresource provided by the semi-persistent assignment. For example, theNode B may send new transmissions at a periodic rate in subframes t₁,t₂=t₁+M, t₃=t₁+2M, . . . , and t_(L)=t₁+L·M, where parameters M and Land/or the semi-persistent scheduling interval may be configured. Forexample, in LTE, parameter M may be configured by upper layers (e.g.,RRC). The UE may send ACK information in corresponding subframes t₁+Q,t₂+Q, t₃+Q, . . . , and t_(L)+Q with the assigned ACK resource.

The Node B may also send retransmissions of data during thesemi-persistent scheduling period and may send scheduling informationfor each retransmission of data, e.g., in the same manner as for dynamicscheduling. The UE may send ACK information for each retransmission ofdata with the ACK resource associated with the first CCE carrying thescheduling information for that retransmission.

In an aspect, an ACK resource assignment for semi-persistent schedulingmay be sent by re-using at least one existing field of a schedulingmessage. The scheduling message may include a number of fields to carryscheduling information for dynamic scheduling. To simplify operation,the scheduling message may also be used to send a semi-persistentassignment for semi-persistent scheduling. At least one field normallyused to carry scheduling information for dynamic scheduling may bere-used to carry an ACK resource assignment for semi-persistentscheduling.

Various formats may be defined for the scheduling message and may beapplicable for different operating scenarios. Each format may include aspecific set of fields for a set of parameters for schedulinginformation.

FIG. 4A shows a scheduling message 410 in accordance with Formats 1 and1A defined by LTE. Formats 1 and 1A may be used to schedule transmissionof one transport block on the PDSCH. Message 410 includes a resourceblock assignment field, an HARQ process number field, a modulation andcoding scheme (MCS) field, a new data indicator field, a redundancyversion field, and a transmit power control (TPC) command field. Theredundancy version field and the new data indicator field may beconsidered as belonging in a retransmission sequence number field.Message 410 may also include other fields, which are not shown in FIG.4A for simplicity.

For HARQ, a number of HARQ processes may be defined. Each HARQ processmay be used to send a new transmission and all retransmissions of atransport block. An HARQ process may be started for a transport block ifthe HARQ process is available and may terminate when the transport blockis decoded correctly. The transport block may be encoded in accordancewith an MCS selected for the transport block to obtain a codeword. Thecodeword may be partitioned into multiple redundancy versions, and eachredundancy version may contain different encoded information (or codebits) for the transport block. A Node B may select one redundancyversion to send for a transmission of the transport block.

Table 1 lists the fields of scheduling message 410 and provides a shortdescription for each field. Table 1 also gives the size of each field innumber of bits.

TABLE 1 Scheduling Message Fields Size Description Resource blockvariable Indicate resource block(s) used to send a assignment transportblock. HARQ process 3 bits Indicate HARQ process on which the transportnumber block is sent. Modulation and 5 bits Indicate modulation schemeand code rate for coding scheme the transport block. New data 1 bitIndicate whether the current transmission is a indicator retransmissionof the transport block. Redundancy 2 bits Indicate redundancy versionbeing sent for the version transport block. TPC command 2 bits Indicatetransmit power adjustment for the PUCCH sent by a recipient UE.

FIG. 4B shows a scheduling message 420 in accordance with Formats 2 and2A defined by LTE. Formats 2 and 2A may be used to schedule atransmission of one or two transport blocks on the PDSCH in a spatialmultiplexing mode. Message 420 includes a resource block assignmentfield, a TPC command field, an HARQ process number field, and two setsof fields for two transport blocks. Each set includes an MCS field, anew data indicator field, and a redundancy version field. Message 420may also include other fields, which are not shown in FIG. 4B forsimplicity. The fields in message 420 are described in Table 1.

FIGS. 4A and 4B show two formats that may be used for sending schedulinginformation. Other formats may also be used and may include differentfields than those shown in FIGS. 4A and 4B. For clarity, much of thedescription below refers to scheduling messages 410 and 420.

For dynamic scheduling, message 410 or 420 may be used to sendscheduling information for a transmission of data. A suitable schedulingmessage may be selected based on whether one or multiple transportblocks are sent and/or other considerations. For semi-persistentscheduling, message 410 or 420 may be used to send a semi-persistentassignment with the first transmission of data. At least one field ofmessage 410 or 420 may be used to send an ACK resource assignment. Ingeneral, any field(s) may be used to send the ACK resource assignment.However, it may be desirable to select a field that is not relevant (ornot as relevant) for semi-persistent scheduling. For example, a fieldthat may be less applicable for the first transmission of data and/ormay have little adverse effect on performance may be selected. Thenumber of fields to select may be dependent on the number of bits neededto send the ACK resource assignment.

In one design, an ACK resource assignment may be sent in the new dataindicator field, the redundancy version field, and the TPC commandfield. In the design shown in FIGS. 4A and 4B, five bits are availablefor these three fields. Up to 32 ACK resources may be configured ordefined and assigned indices of 0 to 31. The configured ACK resourcesmay be broadcast to the UEs or known a priori by the UEs. A 5-bit ACKresource index for one of up to 32 possible ACK resources may be sent inthe three fields to a UE. The UE may obtain the ACK resource index fromthe three fields and may determine the ACK resource assigned to the UEbased on the ACK resource index and the configured ACK resources. The UEmay use the ACK resource to send ACK information during thesemi-persistent scheduling period.

In another design, an ACK resource assignment may be sent in the newdata indicator field, the redundancy version field, the TPC commandfield and all or a subset of the MCS field. For example, two bits in theMCS field may be used in conjunction with the five bits from the otherthree fields. Up to 128 ACK resources may then be configured with theseven bits in the four fields. A 7-bit ACK resource index for one of upto 128 configured ACK resources may be sent in the four fields to a UE.The MCS field can normally convey one of up to 32 MCS values for dynamicscheduling. A set of 8 MCS values may be supported for semi-persistentscheduling and may be configured by higher layers, e.g., RRC. One MCSvalue may be selected from the set of 8 MCS values and may be conveyedwith three remaining bits in the MCS field. As another example, up to 64ACK resources may be configured with five bits in the three fields andone bit in the MCS field. A set of 16 MCS values may be supported forsemi-persistent scheduling, and one MCS value may be selected andconveyed with four remaining bits in the MCS field.

In yet another design, an ACK resource assignment may be sent using twobits in the new data indicator field and the redundancy version field,one bit in the TPC command field, and three bits in the MCS field. Up to64 ACK resources may be configured with the six bits in the four fields.A 6-bit ACK resource index for one of up to 64 configured ACK resourcesmay be sent using the six bits in the four fields to a UE. In yetanother design, an ACK resource assignment may be sent in the TPCcommand field. Two bits are available in the TPC command field. Hence,up to four ACK resources may be configured and assigned indices of 0 to3. A 2-bit ACK resource index for one of up to four configured ACKresources may be sent in the TPC command field to a UE.

In general, any combination of fields and/or bits may be used to send anACK resource assignment for semi-persistent scheduling. If N bits areavailable to send the ACK resource assignment, then up to 2^(N) ACKresources may be configured (e.g., by RRC) and may be assigned indicesof 0 through 2^(N)−1. The configured ACK resources may be broadcast tothe UEs or known a priori by the UEs. An N-bit ACK resource index for anassigned ACK resource may be sent using the N available bits.

A scheduling message may carry scheduling information for dynamicscheduling or a semi-persistent assignment for semi-persistentscheduling. Various mechanisms may be used to indicate whether thescheduling message is sent for dynamic scheduling or semi-persistentscheduling. In one design, different scrambling mechanisms may be usedfor the scheduling message for dynamic scheduling and semi-persistentscheduling. In another design, the scheduling message may include aspecial bit to indicate whether the message is for dynamic scheduling orsemi-persistent scheduling. In yet another design, a designated cellradio network temporary identifier (C-RNTI), which may be referred to asa semi-persistent C-RNTI, may be used to indicate a semi-persistentassignment. Each UE in a given cell may be assigned a unique C-RNTI foruse as a UE identity for that cell. Each UE that has semi-persistentscheduling enabled may also be assigned a unique semi-persistent C-RNTI.A Node B may send a scheduling message to a specific UE for dynamicscheduling by using the normal C-RNTI for the UE or for semi-persistentscheduling by using the semi-persistent C-RNTI for the UE. Each UE maydetect for scheduling messages from the Node B with the normal C-RNTIfor that UE. Each UE that has semi-persistent scheduling enabled mayalso detect for scheduling messages with the semi-persistent C-RNTI forthat UE. In one design, unused fields and/or unused bits in a schedulingmessage for semi-persistent scheduling may be set to designated values.For example, the new data indicator field, the HARQ process numberfield, and the redundancy version field of the scheduling message may beset to designated values of all zeros for semi-persistent scheduling.The designated values may be used by a recipient UE to validate thescheduling message as being for semi-persistent scheduling for that UE(instead of dynamic scheduling for another UE).

FIG. 5 shows a block diagram of a design of a processing unit 500 forgenerating and processing a scheduling message for semi-persistentscheduling. Within processing unit 500, a mapper 510 may receive asemi-persistent assignment comprising semi-persistent schedulinginformation (e.g., a resource block assignment, an MCS, etc.) and an ACKresource assignment for a UE. Mapper 510 may map the ACK resourceassignment to at least one field of a scheduling message and may map thescheduling information to remaining fields and bits of the schedulingmessage. Mapper 510 may also set unused fields and/or unused bits of thescheduling message to designated values (e.g., all zeros). A cyclicredundancy check (CRC) generator 512 may receive the scheduling messagefrom mapper 510, generate a CRC for the message, and append the CRC tothe message. A scrambler 514 may receive a semi-persistent C-RNTI for arecipient UE, generate scrambling bits based on the semi-persistentC-RNTI, and scrambles the scheduling message and CRC with the scramblingbits. An encoder 516 may encode the scrambled scheduling message andprovide an encoded message, which may be further processed and sent onthe PDCCH.

FIG. 5 shows an exemplary design of a processing unit for generating andprocessing a scheduling message for semi-persistent scheduling. Thescheduling message may also be generated and processed in other manners.

FIG. 6 shows a design of a process 600 for receiving data withsemi-persistent scheduling. Process 600 may be performed by a UE (asdescribed below) or by some other entity. The UE may receive asemi-persistent assignment that may be valid for multiple transmissionsof data (block 612). The semi-persistent assignment may comprise a setof parameters for sending the multiple transmissions of data to the UE,e.g., all or some of the parameters shown in Table 1 and/or otherparameters. The semi-persistent assignment may also comprise anassignment of ACK resource. The UE may obtain the assignment of ACKresource from the semi-persistent assignment (block 614). The ACKresource may be assigned to the UE for the multiple transmissions ofdata. The UE may receive a transmission of data sent in accordance withthe semi-persistent assignment (block 616). The UE may process thereceived transmission and determine ACK information for the transmissionof data (block 618). The transmission of data may be for one or moretransport blocks, and the ACK information may indicate whether eachtransport block was decoded correctly or in error by the UE. The UE maysend the ACK information with the ACK resource (block 620). The UE mayreceive additional transmissions of data sent in accordance with thesemi-persistent assignment. The UE may send ACK information for theseadditional transmissions of data with the ACK resource.

In one design of block 612, the UE may receive a scheduling messagecarrying the semi-persistent assignment. In one design, the UE maydetect for the scheduling message for semi-persistent scheduling basedon a C-RNTI used for semi-persistent scheduling. In another design, theUE may determine that the scheduling message is for semi-persistentscheduling based on different scrambling, a special bit, etc. Thescheduling message may also be used to send scheduling information for asingle transmission of data with dynamic scheduling. For dynamicscheduling, the ACK resource may be determined based on the resources(e.g., a starting CCE) used to send the scheduling message.

In one design of block 614, the UE may obtain an index of the ACKresource assigned to the UE from at least one field of the schedulingmessage. The UE may determine the ACK resource based on the index and aset of configured ACK resources (e.g., configured by RRC). The at leastone field may include a new data indicator field, a redundancy versionfield, an MCS field, a TPC command field, other fields, or anycombination thereof.

In one design, for LTE, the UE may receive the semi-persistentassignment on the PDCCH and may receive the transmission of data on thePDSCH. The ACK resource may be for the PUCCH. The UE may also receivethe semi-persistent assignment and the transmission of data on otherdownlink channels and may send ACK information on other uplink channels.

FIG. 7 shows a design of an apparatus 700 for receiving data in awireless communication system. Apparatus 700 includes a module 712 toreceive a semi-persistent assignment valid for multiple transmissions ofdata for a UE, a module 714 to obtain an assignment of ACK resource fromthe semi-persistent assignment, with the ACK resource being assigned tothe UE for the multiple transmissions of data, a module 716 to receive atransmission of data sent in accordance with the semi-persistentassignment, a module 718 to determine ACK information for thetransmission of data, and a module 720 to send the ACK information withthe ACK resource.

FIG. 8 shows a design of a process 800 for receiving data with dynamicscheduling and semi-persistent scheduling. Process 800 may be performedby a UE (as described below) or by some other entity. The UE may receivea first scheduling message carrying scheduling information for a singletransmission of data with dynamic scheduling (block 812). The UE mayreceive a first transmission of data sent in accordance with thescheduling information (block 814). The UE may send first ACKinformation for the first transmission of data with first ACK resourceassociated with a resource (e.g., a CCE) used to send the firstscheduling message (block 816). The first ACK resource may be valid fora single transmission of ACK information.

The UE may also receive a second scheduling message carrying asemi-persistent assignment for multiple transmissions of data withsemi-persistent scheduling (block 818). The UE may receive a secondtransmission of data sent in accordance with the semi-persistentassignment (block 820). The UE may send second ACK information for thesecond transmission of data with second ACK resource conveyed by thesemi-persistent assignment (block 822). The UE may receive additionaltransmissions of data sent in accordance with the semi-persistentassignment. The UE may send ACK information for these additionaltransmissions of data with the second ACK resource, which may be validfor multiple transmissions of ACK information.

In one design, the UE may obtain an index of the second ACK resourcefrom at least one field of the second scheduling message. The first andsecond scheduling messages may have the same format (e.g., as shown inFIG. 4A or 4B) or different formats (e.g., as shown in FIGS. 4A and 4B).These scheduling messages may include the at least one field and one ormore additional fields. The at least one field may carry an ACK resourceindex for semi-persistent scheduling and may carry schedulinginformation for dynamic scheduling.

In one design, the UE may detect for the first scheduling message basedon a first C-RNTI assigned to the UE. The UE may detect for the secondscheduling message based on a second C-RNTI assigned to the UE forsemi-persistent scheduling. The UE may also determine whether ascheduling message is for dynamic scheduling or semi-persistentscheduling based on other mechanisms, e.g., different scrambling, aspecial bit in the scheduling message, etc.

In one design, the UE may obtain a first MCS value from the firstscheduling message and may process the first transmission of data inaccordance with the first MCS value. The first MCS value may be one of afirst plurality of MCS values applicable for dynamic scheduling. The UEmay obtain a second MCS value from the second scheduling message and mayprocess the second transmission of data in accordance with the secondMCS value. The second MCS value may be one of a second plurality of MCSvalues applicable for semi-persistent scheduling. The second pluralityof MCS values may be fewer than the first plurality of MCS values, andthe second MCS value may be sent with fewer bits than the first MCSvalue.

FIG. 9 shows a design of an apparatus 900 for receiving data in awireless communication system. Apparatus 900 includes a module 912 toreceive a first scheduling message carrying scheduling information for asingle transmission of data, a module 914 to receive a firsttransmission of data sent in accordance with the scheduling information,a module 916 to send first ACK information for the first transmission ofdata with first ACK resource associated with a resource used to send thefirst scheduling message, a module 918 to receive a second schedulingmessage carrying a semi-persistent assignment for multiple transmissionsof data, a module 920 to receive a second transmission of data sent inaccordance with the semi-persistent assignment, and a module 922 to sendsecond ACK information for the second transmission of data with secondACK resource conveyed by the semi-persistent assignment.

FIG. 10 shows a design of a process 1000 for sending data withsemi-persistent scheduling. Process 1000 may be performed by a Node B(as described below) or by some other entity. The Node B may assign ACKresource to a UE for semi-persistent scheduling (block 1012). The Node Bmay send a semi-persistent assignment comprising the ACK resource to theUE (block 1014). The semi-persistent assignment may be valid formultiple transmissions of data. The ACK resource may be assigned to theUE for the multiple transmissions of data. The Node B may send atransmission of data in accordance with the semi-persistent assignmentto the UE (block 1016). The Node B may receive ACK information for thetransmission of data, with the ACK information being sent by the UE withthe ACK resource (block 1018). The Node B may send additionaltransmissions of data in accordance with the semi-persistent assignment.The Node B may receive ACK information for these additionaltransmissions of data on the ACK resource.

In one design of block 1014, the Node B may map an index of the ACKresource assigned to the UE to at least one field of a schedulingmessage. The at least one field may include a new data indicator field,a redundancy version field, an MCS field, a TPC command field, and/orother fields. The Node B may map remaining information for thesemi-persistent assignment to remaining fields and bits of thescheduling message. In one design, the Node B may process the schedulingmessage based on a C-RNTI used for semi-persistent scheduling. The NodeB may also indicate that the scheduling message is for semi-persistentscheduling based on other mechanisms. The Node B may send the schedulingmessage to the UE. The scheduling message may also be used to sendscheduling information for dynamic scheduling.

In one design, for LTE, the Node B may send the semi-persistentassignment on the PDCCH and may send the transmission of data on thePDSCH. The ACK resource may be for the PUCCH. The Node B may also sendthe semi-persistent assignment and the transmission of data on otherdownlink channels and may receive ACK information on other uplinkchannels.

FIG. 11 shows a design of an apparatus 1100 for sending data in awireless communication system. Apparatus 1100 includes a module 1112 toassign ACK resource to a UE, a module 1114 to send a semi-persistentassignment comprising the ACK resource to the UE, the semi-persistentassignment being valid for multiple transmissions of data, the ACKresource being assigned to the UE for the multiple transmissions ofdata, a module 1116 to send a transmission of data in accordance withthe semi-persistent assignment to the UE, and a module 1118 to receiveACK information for the transmission of data, the ACK information beingsent by the UE with the ACK resource.

FIG. 12 shows a design of a process 1200 for sending data with dynamicscheduling and semi-persistent scheduling. Process 1200 may be performedby a Node B (as described below) or by some other entity. The Node B maysend to a UE a first scheduling message carrying scheduling informationfor a single transmission of data (block 1212). The Node B may send afirst transmission of data in accordance with the scheduling informationto the UE (block 1214). The Node B may receive first ACK information forthe first transmission of data, with the first ACK information beingsent by the UE with first ACK resource associated with a resource (e.g.,a CCE) used to send the first scheduling message (block 1216). The firstACK resource may be valid for a single transmission of ACK information.

The Node B may send to the UE a second scheduling message carrying asemi-persistent assignment for multiple transmissions of data (block1218). The Node B may send a second transmission of data in accordancewith the semi-persistent assignment to the UE (block 1220). The Node Bmay receive second ACK information for the second transmission of data,with the second ACK information being sent by the UE with second ACKresource conveyed by the semi-persistent assignment (block 1222). TheNode B may send additional transmissions of data in accordance with thesemi-persistent assignment. The Node B may receive ACK information forthese additional transmissions of data on the second ACK resource, whichmay be valid for multiple transmissions of ACK information.

In one design of block 1218, the Node B may map an index of the secondACK resource to at least one field of the second scheduling message. Thefirst and second scheduling messages may have the same format ordifferent formats and may include the at least one field and one or moreadditional fields. The at least one field may carry an ACK resourceindex for semi-persistent scheduling and may carry schedulinginformation for dynamic scheduling.

In one design, the Node B may process (e.g., scramble a CRC for) thefirst scheduling message with a first C-RNTI assigned to the UE. TheNode B may process the second scheduling message with a second C-RNTIassigned to the UE for semi-persistent scheduling. The Node B may alsoindicate whether a scheduling message is for dynamic scheduling orsemi-persistent scheduling based on other mechanisms.

In one design, the Node B may select a first MCS value from a firstplurality of MCS values applicable for dynamic scheduling. The Node Bmay process the first transmission of data in accordance with the firstMCS value. The Node B may select a second MCS value from a secondplurality of MCS values applicable for semi-persistent scheduling. TheNode B may process the second transmission of data in accordance withthe second MCS value. The second plurality of MCS values may be fewerthan the first plurality of MCS values.

FIG. 13 shows a design of an apparatus 1300 for sending data in awireless communication system. Apparatus 1300 includes a module 1312 tosend to a UE a first scheduling message carrying scheduling informationfor a single transmission of data, a module 1314 to send a firsttransmission of data in accordance with the scheduling information tothe UE, a module 1316 to receive first ACK information for the firsttransmission of data on first ACK resource associated with a resourceused to send the first scheduling message, a module 1318 to send to theUE a second scheduling message carrying a semi-persistent assignment formultiple transmissions of data, a module 1320 to send a secondtransmission of data in accordance with the semi-persistent assignmentto the UE, and a module 1322 to receive second ACK information for thesecond transmission of data on second ACK resource conveyed by thesemi-persistent assignment.

The modules in FIGS. 7, 9, 11 and 13 may comprise processors,electronics devices, hardware devices, electronics components, logicalcircuits, memories, software codes, firmware codes, etc., or anycombination thereof.

The techniques described herein may allow for efficient assignment ofACK resources for semi-persistent scheduling. For dynamic scheduling,ACK resources may be associated with CCEs carrying schedulinginformation and may be conveniently assigned to UEs without incurringadditional signaling overhead. This is possible when each transmissionof data on the PDSCH is scheduled with scheduling information sent onthe PDCCH. For semi-persistent scheduling, a semi-persistent assignmentmay be sent once on the PDCCH with the first transmission of data, andno scheduling information may be sent for subsequent new transmissionsof data. In this case, the ACK resources for the subsequent newtransmissions of data cannot be associated with the CCEs carryingscheduling information and may be provided by the semi-persistentassignment, as described above.

The techniques described herein allow for dynamic assignment of ACKresources for semi-persistent scheduling using Layer 1 signaling sent onthe PUCCH, as described above. The techniques may be more efficient (interms of overhead) than assigning ACK resources for semi-persistentscheduling using Layer 3 (e.g., RRC) signaling. The techniques may alsobe more efficient (in terms of resource usage) than statically assigningeach active UE with ACK resource for semi-persistent scheduling.

FIG. 14 shows a block diagram of a design of a Node B 110 and a UE 120,which may be one of the Node Bs and one of the UEs in FIG. 1. In thisdesign, Node B 110 is equipped with T antennas 1434 a through 1434 t,and UE 120 is equipped with R antennas 1452 a through 1452 r, where ingeneral T≧1 and R≧1.

At Node B 110, a transmit processor 1420 may receive data (e.g.,transport blocks) for one or more UEs from a data source 1412, processthe data for each UE based on one or more MCS values for that UE, andprovide data symbols for all UEs. Transmit processor 1420 may alsoprocess control information (e.g., scheduling messages for dynamicscheduling and semi-persistent scheduling) from a controller/processor1440 and provide control symbols. A transmit (TX) multiple-inputmultiple-output (MIMO) processor 1430 may multiplex the data symbols,the control symbols, and/or pilot symbols. TX MIMO processor 1430 mayperform spatial processing (e.g., precoding) on the multiplexed symbols,if applicable, and provide T output symbol streams to T modulators(MODs) 1432 a through 1432 t. Each modulator 1432 may process arespective output symbol stream (e.g., for OFDM) to obtain an outputsample stream. Each modulator 1432 may further process (e.g., convert toanalog, amplify, filter, and upconvert) the output sample stream toobtain a downlink signal. T downlink signals from modulators 1432 athrough 1432 t may be transmitted via T antennas 1434 a through 1434 t,respectively.

At UE 120, antennas 1452 a through 1452 r may receive the downlinksignals from Node B 110 and provide received signals to demodulators(DEMODs) 1454 a through 1454 r, respectively. Each demodulator 1454 maycondition (e.g., filter, amplify, downconvert, and digitize) arespective received signal to obtain input samples. Each demodulator1454 may further process the input samples (e.g., for OFDM) to obtainreceived symbols. A MIMO detector 1456 may obtain received symbols fromall R demodulators 1454 a through 1454 r, perform MIMO detection on thereceived symbols if applicable, and provide detected symbols. A receiveprocessor 1458 may process (e.g., demodulate, deinterleave, and decode)the detected symbols, provide decoded data for UE 120 to a data sink1460, and provide decoded control information to a controller/processor1480.

On the uplink, at UE 120, data from a data source 1462 and controlinformation (e.g., ACK information, etc.) from controller/processor 1480may be processed by a transmit processor 1464, precoded by a TX MIMOprocessor 1466 if applicable, conditioned by modulators 1454 a through1454 r, and transmitted to Node B 110. At Node B 110, the uplink signalsfrom UE 120 may be received by antennas 1434, conditioned bydemodulators 1432, processed by a MIMO detector 1436 if applicable, andfurther processed by a receive processor 1438 to obtain the data andcontrol information transmitted by UE 120.

Controllers/processors 1440 and 1480 may direct the operation at Node B110 and UE 120, respectively. Processor 1480 and/or other processors andmodules at UE 120 may perform or direct process 600 in FIG. 6, process800 in FIG. 8, and/or other processes for the techniques describedherein. Processor 1440 and/or other processors and modules at Node B 110may perform or direct process 1000 in FIG. 10, process 1200 in FIG. 12,and/or other processes for the techniques described herein. Transmitprocessor 1420 may implement processing unit 500 in FIG. 5. Memories1442 and 1482 may store data and program codes for Node B 110 and UE120, respectively. A scheduler 1444 may schedule UEs for downlink and/oruplink transmission and may provide assignments of resources (e.g., ACKresources) for the scheduled UEs.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thedisclosure herein may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination of the two. Asoftware module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal. In the alternative, theprocessor and the storage medium may reside as discrete components in auser terminal.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by ageneral purpose or special purpose computer. By way of example, and notlimitation, such computer-readable media can comprise RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code means in the form of instructions or datastructures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Thus, the disclosure is not intended to be limited tothe examples and designs described herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method for wireless communication at a userequipment (UE), comprising: receiving a scheduling message according toa message format that is associated with both semi-persistentassignments that are valid for multiple transmissions of data anddynamic assignments that are valid for single transmissions of data,wherein the message format comprises a new data indicator field that,for the dynamic assignments, carries information used in processingtransmissions associated with the dynamic assignments, and for thesemi-persistent assignments, is set to a designated value for validationof the semi-persistent assignments; validating that the receivedscheduling message comprises a semi-persistent assignment based at leastin part on a comparison of the new data indicator field to thedesignated value; obtaining an assignment of a first acknowledgement(ACK) resource from a transmit power control (TPC) field of thescheduling message for the semi-persistent assignment; receiving themultiple transmissions of data sent in accordance with thesemi-persistent assignment; determining first ACK information for afirst transmission of data of the multiple transmissions of data; andsending the first ACK information on the first ACK resource.
 2. Themethod of claim 1, wherein the message format further comprises one ormore of: a hybrid automatic repeat request (HARQ) field, a redundancyversion field, a resource block assignment field, or a modulation andcoding scheme (MCS) field.
 3. The method of claim 1, further comprising:detecting the scheduling message based on a semi-persistent schedulingcell radio network temporary identifier assigned to the UE that isdifferent from a cell radio network temporary identifier assigned to theUE for detection of the dynamic assignments.
 4. The method of claim 1,further comprising: receiving a dynamic assignment for a retransmissionof the first transmission of data in a second scheduling message inresponse to indicating that the first transmission of data was decodedin error in the first ACK information; and receiving the retransmissionof the first transmission of data according to the dynamic assignment.5. The method of claim 4, further comprising: obtaining a secondassignment of a second ACK resource based on a resource used to send thesecond scheduling message; and determining second ACK information forthe retransmission of the first transmission of data; and sending thesecond ACK information on the second ACK resource.
 6. The method ofclaim 1, wherein the scheduling message comprising the semi-persistentassignment is received on a physical downlink control channel (PDCCH)and the multiple transmissions of data are received on a physicaldownlink shared channel (PDSCH).
 7. The method of claim 1, furthercomprising: receiving a semi-persistent scheduling interval for themultiple transmissions of data via upper layer signaling.
 8. The methodof claim 1, wherein the designated value comprises all zeros.
 9. Themethod of claim 2, wherein one or more of the HARQ field, the redundancyversion field, the resource block assignment field, the MCS field, orthe TPC command field are set to designated values for the validation ofthe semi-persistent assignments.
 10. A method for wirelesscommunication, comprising: mapping, according to a message format thatis associated with both semi-persistent assignments that are valid formultiple transmissions of data and dynamic assignments that are validfor single transmissions of data, scheduling information for asemi-persistent assignment to a scheduling message intended for a userequipment (UE), wherein the message format comprises a new dataindicator field that, for the dynamic assignments, carries informationused in processing transmissions associated with the dynamicassignments, and for the semi-persistent assignments, is set to adesignated value for validation of the semi-persistent assignments;mapping the new data indicator field to a designated value, wherein thedesignated value indicates that the scheduling message comprises asemi-persistent assignment; mapping an assignment of a firstacknowledgement (ACK) resource to a transmit power control (TPC) commandfield of the scheduling message for the semi-persistent assignment;sending the scheduling message to the UE; sending the multipletransmissions of data to the UE according to the semi-persistentassignment; and receiving first ACK information on the first ACKresource.
 11. The method of claim 10, wherein the message format furthercomprises one or more of: a hybrid automatic repeat request (HARQ)field, a redundancy version field, a resource block assignment field, ora modulation and coding scheme (MCS) field.
 12. The method of claim 10,further comprising: scrambling the scheduling message using asemi-persistent scheduling cell radio network temporary identifierassigned to the UE that is different from a cell radio network temporaryidentifier assigned to the UE for detection of the dynamic assignments.13. The method of claim 12, wherein the scrambling the schedulingmessage using the semi-persistent scheduling cell radio networktemporary identifier assigned to the UE comprises scrambling a cyclicredundancy check (CRC) associated with the scheduling message with thesemi-persistent scheduling cell radio network temporary identifierassigned to the UE.
 14. The method of claim 12, wherein the first ACKinformation indicates that a first transmission of data of the multipletransmissions of data was decoded in error, the method furthercomprising: sending a dynamic assignment for a retransmission of thefirst transmission of data in a second scheduling message to the UE; andsending the retransmission to the UE according to the dynamicassignment.
 15. The method of claim 14, further comprising: receivingsecond ACK information associated with the retransmission on a secondACK resource determined based on a resource used to send the secondscheduling message.
 16. The method of claim 10, wherein the schedulingmessage comprising the semi-persistent assignment is sent on a physicaldownlink control channel (PDCCH) and the multiple transmissions of dataare sent on a physical downlink shared channel (PDSCH).
 17. The methodof claim 10, further comprising: sending a semi-persistent schedulinginterval for the multiple transmissions of data to the UE via upperlayer signaling.
 18. The method of claim 10, wherein the designatedvalue comprises all zeros.
 19. The method of claim 11, wherein one ormore of the HARQ field, the redundancy version field, the resource blockassignment field, the MCS field, or the TPC command field are set todesignated values for the validation of the semi-persistent assignments.20. An apparatus for wireless communication at a user equipment (UE),comprising: at least one processor; a memory coupled to the at least oneprocessor, the memory comprising instructions that, when executed by theat least one processor, cause the at least one processor to: receive ascheduling message according to a message format that is associated withboth semi-persistent assignments that are valid for multipletransmissions of data and dynamic assignments that are valid for singletransmissions of data, wherein the message format comprises a new dataindicator field that, for the dynamic assignments, carries informationused in processing transmission associated with the dynamic assignments,and for the semi-persistent assignments, is set to a designated valuefor validation of the semi-persistent assignments; validate that thereceived scheduling message comprises a semi-persistent assignment basedat least in part on a comparison of the new data indicator field to thedesignated value; obtain an assignment of a first acknowledgement (ACK)resource from a transmit power control (TPC) command field of thescheduling message for the semi-persistent assignment; determine firstACK information for a first transmission of data of the multipletransmissions of data; receive the multiple transmissions of data sentin accordance with the semi-persistent assignment; and send the firstACK information on the first ACK resource.
 21. The apparatus of claim20, wherein the message format further comprises one or more of: ahybrid automatic repeat request (HARQ) field, a redundancy versionfield, a resource block assignment field, or a modulation and codingscheme (MCS) field.
 22. The apparatus of claim 20, wherein the at leastone processor is further configured to: detect the scheduling messagebased on a semi-persistent scheduling cell radio network temporaryidentifier assigned to the UE that is different from a cell radionetwork temporary identifier assigned to the UE for detection of thedynamic assignments.
 23. The apparatus of claim 20, wherein the at leastone processor is further configured to: receive a dynamic assignment fora retransmission of the first transmission of data in a secondscheduling message in response to indicating that the first transmissionof data was decoded in error in the first ACK information; and receivethe retransmission of the first transmission of data according to thedynamic assignment.
 24. The apparatus of claim 23, wherein the at leastone processor is further configured to: obtain a second assignment of asecond ACK resource based on a resource used to send the secondscheduling message; and determine second ACK information for theretransmission of the first transmission of data; and send the secondACK information on the second ACK resource.
 25. The apparatus of claim21, wherein one or more of the HARQ field, the redundancy version field,the resource block assignment field, the MCS field, or the TPC commandfield are set to designated values for the validation of thesemi-persistent assignments.
 26. An apparatus for wirelesscommunication, comprising: at least one processor; a memory coupled tothe at least one processor, the memory comprising instructions that,when executed by the at least one processor, cause the at least oneprocessor to: map, according to a message format that is associated withboth semi-persistent assignments that are valid for multipletransmissions of data and dynamic assignments that are valid for singletransmissions of data, scheduling information for a semi-persistentassignment to a scheduling message intended for a user equipment (UE),wherein the message format comprises a new data indicator field that,for the dynamic assignments, carries information used in processingtransmissions associated with the dynamic assignments, and for thesemi-persistent assignments, is set to a designated value for validationof the semi-persistent assignments; map the new data indicator field toa designated value, wherein the designated value indicates that thescheduling message comprises a semi-persistent assignment; map anassignment of a first acknowledgement (ACK) resource using a transmitpower control (TPC) command field of the scheduling message for thesemi-persistent assignment; send the scheduling message to the UE; andsend the multiple transmissions of data to the UE according to thesemi-persistent assignment; and receive first ACK information on thefirst ACK resource.
 27. The apparatus of claim 26, wherein the messageformat further comprises one or more of: a hybrid automatic repeatrequest (HARQ) field, a redundancy version field, a resource blockassignment field, or a modulation and coding scheme (MCS) field.
 28. Theapparatus of claim 26, wherein the at least one processor is furtherconfigured to: scramble the scheduling message using a semi-persistentscheduling cell radio network temporary identifier assigned to the UEthat is different from a cell radio network temporary identifierassigned to the UE for detection of the dynamic assignments.
 29. Theapparatus of claim 26, wherein the at least one processor is furtherconfigured to scramble a cyclic redundancy check (CRC) associated withthe scheduling message with a semi-persistent scheduling cell radionetwork temporary identifier assigned to the UE for semi-persistentscheduling.
 30. The apparatus of claim 26, wherein the first ACKinformation indicates that a first transmission of data of the multipletransmissions of data was decoded in error, and wherein the processor isfurther configured to: send a dynamic assignment for a retransmission ofthe first transmission of data in a second scheduling message to the UE;and send the retransmission to the UE according to the dynamicassignment.
 31. The apparatus of claim 30, wherein the at least oneprocessor is further configured to: receive second ACK informationassociated with the retransmission on a second ACK resource determinedbased on a resource used to send the second scheduling message.
 32. Theapparatus of claim 27, wherein one or more of the HARQ field, theredundancy version field, the resource block assignment field, the MCSfield, or the TPC command field are set to designated values for thevalidation of the semi-persistent assignments.
 33. A non-transitorycomputer-readable medium for wireless communication at a user equipment(UE), comprising code that, when executed by at least one computer,causes the at least one computer to: receive a scheduling messageaccording to a message format that is associated with bothsemi-persistent assignments that are valid for multiple transmissions ofdata and dynamic assignments that are valid for single transmissions ofdata, wherein the message format comprises a new data indicator fieldthat, for the dynamic assignments, carries information used inprocessing transmissions associated with the dynamic assignments, andfor the semi-persistent assignments, is set to a designated value forvalidation of the semi-persistent assignments; validate that thereceived scheduling message comprises a semi-persistent assignment basedat least in part on a comparison of the new data indicator field to thedesignated value; obtain an assignment of a first acknowledgement (ACK)resource from a transmit power control (TPC) command field of thescheduling message for the semi-persistent assignment; receive themultiple transmissions of data sent in accordance with thesemi-persistent assignment; determine first ACK information for a firsttransmission of data of the multiple transmissions of data; and send thefirst ACK information on the first ACK resource.
 34. A non-transitorycomputer-readable medium for wireless communication comprising codethat, when executed by at least one computer, causes the at least onecomputer to: map, according to a message format that is associated withboth semi-persistent assignments that are valid for multipletransmissions of data and dynamic assignments that are valid for singletransmissions of data, scheduling information for a semi-persistentassignment to a scheduling message intended for a user equipment (UE),wherein the message format comprises a new data indicator field that,for the dynamic assignments, carries information used in processingtransmissions associated with the dynamic assignments, and for thesemi-persistent assignments, is set to a designated value for validationof the semi-persistent assignments; map the new data indicator field toa designated value, wherein the designated value indicates that thescheduling message comprises a semi-persistent assignment; map anassignment of a first acknowledgement (ACK) resource using a transmitpower control (TPC) command field of the scheduling message for thesemi-persistent assignment; send the scheduling message to the UE; sendthe multiple transmissions of data to the UE according to thesemi-persistent assignment; and receive first ACK information on thefirst ACK resource.